Three common types of surgery are typically performed internally within the human body. The traditional open type of surgery involves a large incision through the skin and muscle layers of the patient. The incision is made sufficiently large enough both to allow the surgeon to see into the body and to accommodate the surgeon's hands and instruments. Open surgery is sometimes referred to as invasive surgery.
A second type of surgery, endoscopy, involves inserting a flexible instrument through an existing body orifice to gain access to a passageway in the body such as the trachea, colon, or esophagus. The flexible instrument is typically in the form of a tube containing, at a minimum, a light source, an optical sensor, and a surgical tool such as a scalpel, an electrosurgical probe or a laser light channel. Since no incisions are made in the body, endoscopy is referred to as minimally invasive surgery.
A third related type of surgery is laparoscopy which involves cutting one or more small incisions to gain access to an internal cavity such as the abdominal cavity. To perform laparoscopic surgery in the abdominal cavity, two incisions are made through the abdominal wall of the patient. A plastic sleeve or cannula is inserted into both incisions. One cannula is attached to a gas pump, known as an insufflator. The insufflator pumps gas into the abdomen to expand the abdominal wall above the internal organs and create a cavity within which the surgical procedure is performed. Both cannulas allow instruments to be inserted into the abdominal cavity, manipulated to accomplish the surgical procedure and removed without further injury to the patient's skin and muscle layers. A light source and optical sensor are usually inserted through one of the cannulas. With the light source and sensor, the surgeon watches a video monitor to see the interior of the abdominal cavity. At the conclusion of the procedure, the instruments are removed, the abdominal cavity is deflated and the cannulas are removed. The only remaining outward effects of surgery are the two small incisions. For this reason, laparoscopy is also referred to as minimally invasive surgery.
It is common during minimally invasive surgery to deliver gas or liquid to irrigate the surgical site and wash away debris or other fluid. Aspiration is also typically used to remove smoke, debris or fluids such as blood or mucus. Aspiration involves suctioning gas, liquid and debris away from the surgical site and out of the body. Irrigation and aspiration are accomplished by placing the distal end of a tube at the surgical site and delivering fluid to the site or sucking fluid or other material away from the surgical site, by creating a positive or a negative pressure at the distal end of the tube, respectively.
The flow of fluid during irrigation and aspiration is typically controlled by the surgeon manually depressing valves which are located in a handle attached to the tube or which are associated with the tube. The tube and the handle are sometimes referred to as the probe. Such valves, which commonly use sliding O-rings to create seals, have several disadvantages. O-rings, when not in use, such as during storage and shipping to a hospital, may become stuck to the surrounding passageway or become flattened thereby causing an ineffective seal. The initial use of an instrument with O-rings may, therefore, be erratic and unsatisfactory. Further, the O-rings may not slide easily, causing difficulty in control and operator fatigue. Debris passing through the valves during aspiration may interfere with proper sealing.
During surgery the surgeon may experience distraction or discomfort from holding the probe in an awkward position or while holding down the valve control buttons on the probe. The relatively long instruments which must be manipulated during minimally invasive surgery may require some degree of added effort and facility to manipulate. The surgeon often is required to hold the handle in unusual or uncomfortable positions above the patient while performing the procedure. Holding the valve control buttons in a fixed position for a long period of time may cause discomfort. Since the fingers must firmly hold the control buttons in a fixed position, the instrument cannot be easily shifted around and re-gripped during the procedure, without releasing the control buttons.
Minimally invasive irrigator/aspirator probes may either be reusable or disposable after a single procedure. Disposable instruments are sometimes regarded as desirable because of the inconvenience of having to sterilize the instrument before each use. Autoclaving is the typical method of sterilizing an instrument and it involves placing the instruments in an oven-like device to heat them to an elevated temperature under pressure for a period of time to eliminate all of the bacteria and viruses on or in the instrument. Although disposing of surgical instruments after a single use may be regarded as an unnecessary expense, the autoclaving procedure itself involves the expense of human salary and time. Some surgical instruments are so expensive that they are only available as reusable instruments. Further, some surgical instruments are so complex that they must be disassembled for autoclaving and then reassembled afterwards. The assembly and disassembly procedure also adds to the cost of use of such instruments.
Minimally invasive irrigator/aspirator surgical probes present issues relating to both dispensable instruments and reusable instruments. The complex valve structure which may contain debris from aspiration is particularly difficult to sterilize without time consuming disassembly of the probe. Other pares of the probe can easily be autoclaved.
It is against this background information, and the desire to produce a more convenient minimally invasive surgical probe, that the present invention has resulted.